Differential oil change

[DanW]

@CarbonSteel
@others

New kid in town...

Valvoline FlexFill Extended Protection Full Synthetic 75W-140 Gear Oil 1 Quart Pouch

https://www.amazon.com/Valvoline-Fl...+Gear+Oil+1+Quart+Pouch&qid=1761872699&sr=8-1

Interesting. I wonder what they are doing differently?

I'm coming up on diff fluid changes soon in both Jeeps. I was going to go with Mobil 1 75w140 because Rural King has it for about $13 a quart. Then they put the Valvoline (previous version in the bag) on sale for about the same. Gotta say, I LOVE that bag. So much that I was going to use an old empty bag and put the M1 in it to squirt it into the diffs.

I wonder if they put some PAO into the base oil of this new version?

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[Rhinebeck01]

Interesting. I wonder what they are doing differently?

I'm coming up on diff fluid changes soon in both Jeeps. I was going to go with Mobil 1 75w140 because Rural King has it for about $13 a quart. Then they put the Valvoline (previous version in the bag) on sale for about the same. Gotta say, I LOVE that bag. So much that I was going to use an old empty bag and put the M1 in it to squirt it into the diffs.

I wonder if they put some PAO into the base oil of this new version?

@DanW

Authored by Valvoline:

Valvoline Extended Protection Flexfill Full Synthetic Gear Oil


You asked, we listened. DIYers said they wanted a premium gear oil in an easy-to-use package. Valvoline delivered with Extended Protection Flexfill Full Synthetic Gear Oil, providing up to 4X better gear wear protection than our conventional formulation. Unlike the industry-leading premium gear oil, Valvoline Extended Protection Flexfill Gear Oil features an innovative flexible pouch for reaching tight, hard-to-reach spaces with less waste. The high-performance formula combines superior-quality synthetic base stocks and additives for outstanding high and low temperature protection and superb thermal stability in demanding environments like towing, hauling or off-roading. So no matter where the road takes you, Valvoline Extended Protection Gear Oil is proven to maximize gear life. Our additive technology delivers extreme pressure protection, better load carrying capacity and wear resistance, plus excellent corrosion protection, while the anti-foaming agent improves lubrication for quieter, smooth-running gears. Now, Valvoline offers the best of both gear oil worlds: A premium full synthetic product in the preferred Flex fill package. No waste, no mess, no cone-shaped containers. Only from Valvoline – the #1 gear oil brand. Available in SAE 75W-90 and SAE 75W-140.

 

[DanW]

From what I can tell with the previous version, there was no PAO in the base oil. It looks like between 10% and 30% group III, if I understand correctly. And I also cannot tell if that is the bag version or the bottle version. They seem to be slightly different, according to the PDS.

 

[Rhinebeck01]

From what I can tell with the previous version, there was no PAO in the base oil. It looks like between 10% and 30% group III, if I understand correctly. And I also cannot tell if that is the bag version or the bottle version. They seem to be slightly different, according to the PDS.

@DanW

Valvoline's Customer Service is good about fielding such questions.

I'm on the road/interstate traveling presently and it is not a convenient time for me to call them..

You can contact Valvoline through their Customer Service phone number 1-800-VALVOLINE.

IF you or anyone calls them, I'd be interested in hearing what they have to say..

 

[DanW]

@DanW

Valvoline's Customer Service is good about fielding such questions.

I'm on the road/interstate traveling presently and it is not a convenient time for me to call them..

You can contact Valvoline through their Customer Service phone number 1-800-VALVOLINE.

IF you or anyone calls them, I'd be interested in hearing what they have to say..

I'll give them a call! Thanks!

I'm very curious about it since I'll be purchasing gear oil very soon. I will let you know what I hear.

 

[CarbonSteel]

Just wish it was still a US owned company...

 

[Sopwith Guy]

I did both my axles last month and this is what I used. I wanted the best and I feel confident this is it.

 

[jadmt]

getting ready to head to Moab on Monday so decided to change the rear diff oil..I am at 20,000 miles and changed it about 10,000 miles ago and had some deep water and a previous Moab trip on the last change..I have been using 75-85 Mopar gear oil (been using that for years on previous jk's and my power wagon) but figured with the new 37's (116lbs a tire wheel combo)I just put on and knowing I will be driving 80mph to and from Moab decided to use Valvoline 75-140 ($15 a quart at walmart) this go round. as someone said I will be keeping one of the empty bags to transfer gear oil to for my next change...super easy with those bags...after 10,000 miles the gear oil looked like new...48 oz out 48 oz in......always seems like too little but that is what it takes....new gasket is only $15.60 at my jeep dealership so I went ahead and used a new gasket altho the old which had two changes on it looked new and I just cleaned it up and will alternate between the old one and the one I put on today....

 

[jadmt]

just got back from Moab...something I noticed..I have a 24 jlur 4.10 gears, my buddy a 23 jlur 4.56 gears...I used the Valvoline 75-140 he used amsoil extreme 75-140 and after running 70-80mph for hundreds of miles non stop I felt his diff cover to compare to mine...his was hot enough could not keep your hand on it..mine was warm but not so hot you couldn't keep your hand on it....I have an AEV diff cover he has stock cover...so does the thicker diff cover just dissipate the heat better than the stock cover or is it holding heat in? I wish I would have brought my temp gun... it would have been interesting to see the actual oil temps. I know this all means diddly squat but just an observation...

 

[Aonarch]

just got back from Moab...something I noticed..I have a 24 jlur 4.10 gears, my buddy a 23 jlur 4.56 gears...I used the Valvoline 75-140 he used amsoil extreme 75-140 and after running 70-80mph for hundreds of miles non stop I felt his diff cover to compare to mine...his was hot enough could not keep your hand on it..mine was warm but not so hot you couldn't keep your hand on it....I have an AEV diff cover he has stock cover...so does the thicker diff cover just dissipate the heat better than the stock cover or is it holding heat in? I wish I would have brought my temp gun... it would have been interesting to see the actual oil temps. I know this all means diddly squat but just an observation...

Your cover is nodular iron and his is stamped steel?

Nodular iron cover absorbs the heat better and can help keep your gear set cooler, since that 80 mph air is hitting it while driving, cooling it off. Your cover pulls heat away from the gear set.

Stamped steel keeps the fluid in the diff as long as you don't hit anything. No other benefits.

 

[jadmt]

Your cover is nodular iron and his is stamped steel?

Nodular iron cover absorbs the heat better and can help keep your gear set cooler, since that 80 mph air is hitting it while driving, cooling it off. Your cover pulls heat away from the gear set.

Stamped steel keeps the fluid in the diff as long as you don't hit anything. No other benefits.

does it though? no clean air is hitting the backside of the rear diff cover at speed. be interesting to see what actual lube temps were..maybe it does but also could be the diff between gear ratios and maybe lube or maybe nothing in the grand scheme of things

 

[grimmjeeper]

just got back from Moab...something I noticed..I have a 24 jlur 4.10 gears, my buddy a 23 jlur 4.56 gears...I used the Valvoline 75-140 he used amsoil extreme 75-140 and after running 70-80mph for hundreds of miles non stop I felt his diff cover to compare to mine...his was hot enough could not keep your hand on it..mine was warm but not so hot you couldn't keep your hand on it....I have an AEV diff cover he has stock cover...so does the thicker diff cover just dissipate the heat better than the stock cover or is it holding heat in? I wish I would have brought my temp gun... it would have been interesting to see the actual oil temps. I know this all means diddly squat but just an observation...

Are his gears factory or aftermarket? The quality of the install can affect temperature.

Best thing to do is drain and refill his diff with Valvoline, then do a run. Check temps and see if there's a difference.

 

[jadmt]

Are his gears factory or aftermarket? The quality of the install can affect temperature.

Best thing to do is drain and refill his diff with Valvoline, then do a run. Check temps and see if there's a difference.

factory XR...he was not concerned in the least as he has over 30,000 miles on it doing this kind of stuff. both our jeeps are set up the same for the most part..he has a 2.0 and i have 3.6 and same tires etc..he kicks my ass in mpg which makes a difference when traveling as we drive hard usually fill up to fill up and I need gas and he still has 50 miles of range.

 

[roaniecowpony]

The difference in steel and cast iron, in terms of thermal conductivity of just the metal is zero. They both transfer heat at about the same rate.

Gear oil is a poor thermal conductor and transfers heat about about 1/3rd the rate of steel/cast iron.

The thicker cover will take longer to reach full saturation (equilibrium) with the fluid on the inside and air on the outside. But, once both are at steady state, I would guess they are capable of the same heat transfer, since the steel/cast iron transfer heat at nearly 3 times the rate of heat transfer of gear oil, and the surface area of both covers is more or less the same.

I think the observation of one cover being hotter to the touch than the other, even if they both had the same temperature oil inside, is more about the powder coat (polyester plastic coating) vs paint. Plastic is a very poor conductor of heat (insulator). But, frankly, no two differentials will have identical heat output.

 

[grimmjeeper]

The difference in steel and cast iron, in terms of thermal conductivity of just the metal is zero. They both transfer heat at about the same rate.

Gear oil is a poor thermal conductor and transfers heat about about 1/3rd the rate of steel/cast iron.

The thicker cover will take longer to reach full saturation (equilibrium) with the fluid on the inside and air on the outside. But, once both are at steady state, I would guess they are capable of the same heat transfer, since the steel/cast iron transfer heat at nearly 3 times the rate of heat transfer of gear oil, and the surface area of both covers is more or less the same.

I think the observation of one cover being hotter to the touch than the other, even if they both had the same temperature oil inside, is more about the powder coat (polyester plastic coating) vs paint. Plastic is a very poor conductor of heat (insulator). But, frankly, no two differentials will have identical heat output.

Given the rest of the housing is available to soak and dissipate heat means that the diff cover can only have so much impact on it.

Two biggest factors for a dramatic difference in the temperatures of the two differentials, to my way of thinking, is the gears/bearings themselves, and/or the quality of the lubrication.

Bad gear setup (even the factory gets it wrong sometimes) or failing bearings will generate more heat.

If the oil level is low, or if the oil has broken down and it no longer provides adequate lubrication, that will cause excessive wear and premature failure.

If I had the differential that was too hot to touch, I would first check the level. If that was OK, I would drain and refill with fresh oil. Probably a different brand. I'd also check the drained oil for evidence of excessive wear. While I was in there I would visually inspect the gears. If excessive heat persists, I would pull it apart and check bearings.

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